<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
</head>

<body>
	<script>
		function foo(something) {
			this.a = something;
		}

		var obj1 = {};

		var bar = foo.bind(obj1);
		bar(2);
		console.log(obj1.a); // 2

		var baz = new bar(3);
		console.log(obj1.a); // 2
		console.log(baz.a); // 3
	</script>
</body>

</html>